NECTIN4 Amplification Is Frequent in Solid Tumors and Predicts Enfortumab Vedotin Response in Metastatic Urothelial Cancer

PURPOSE

The anti-NECTIN4 antibody-drug conjugate enfortumab vedotin (EV) is approved for patients with metastatic urothelial cancer (mUC). However, durable benefit is only achieved in a small, yet uncharacterized patient subset. NECTIN4 is located on chromosome 1q23.3, and 1q23.3 gains represent frequent copy number variations (CNVs) in urothelial cancer. Here, we aimed to evaluate NECTIN4 amplifications as a genomic biomarker to predict EV response in patients with mUC.

MATERIALS AND METHODS

We established a NECTIN4-specific fluorescence in situ hybridization (FISH) assay to assess the predictive value of NECTIN4 CNVs in a multicenter EV-treated mUC patient cohort (mUC-EV, n = 108). CNVs were correlated with membranous NECTIN4 protein expression, EV treatment responses, and outcomes. We also assessed the prognostic value of NECTIN4 CNVs measured in metastatic biopsies of non-EV-treated mUC (mUC-non-EV, n = 103). Furthermore, we queried The Cancer Genome Atlas (TCGA) data sets (10,712 patients across 32 cancer types) for NECTIN4 CNVs.

RESULTS

NECTIN4 amplifications are frequent genomic events in muscle-invasive bladder cancer (TCGA bladder cancer data set: approximately 17%) and mUC (approximately 26% in our mUC cohorts). In mUC-EV, NECTIN4 amplification represents a stable genomic alteration during metastatic progression and associates with enhanced membranous NECTIN4 protein expression. Ninety-six percent (27 of 28) of patients with NECTIN4 amplifications demonstrated objective responses to EV compared with 32% (24 of 74) in the nonamplified subgroup (P < .001). In multivariable Cox analysis adjusted for age, sex, and Bellmunt risk factors, NECTIN4 amplifications led to a 92% risk reduction for death (hazard ratio, 0.08 [95% CI, 0.02 to 0.34]; P < .001). In the mUC-non-EV, NECTIN4 amplifications were not associated with outcomes. TCGA Pan-Cancer analysis demonstrated that NECTIN4 amplifications occur frequently in other cancers, for example, in 5%-10% of breast and lung cancers.

CONCLUSION

NECTIN4 amplifications are genomic predictors of EV responses and long-term survival in patients with mUC.

Clinical implications of AGR2 in primary prostate cancer: Results from a large-scale study

Human anterior gradient-2 (AGR2) has been implicated in carcinogenesis of various solid tumours, but the expression data in prostate cancer are contradictory regarding its prognostic value. The objective of this study is to evaluate the expression of AGR2 in a large prostate cancer cohort and to correlate it with clinicopathological data. AGR2 protein expression was analysed immunohistochemically in 1023 well-characterized prostate cancer samples with a validated antibody. AGR2 expression levels in carcinomas were compared with matched tissue samples of adjacent normal glands. AGR2 expression levels were dichotomized and tested for statistical significance. Increased AGR2 expression was found in 93.5% of prostate cancer cases. AGR2 levels were significantly higher in prostate cancer compared with normal prostate tissue. A gradual loss of AGR2 expression was associated with increasing tumour grade (ISUP), and AGR2 expression is inversely related to patient survival, however, multivariable significance is not achieved. AGR2 is clearly upregulated in the majority of prostate cancer cases, yet a true diagnostic value appears unlikely. In spite of the negative correlation of AGR2 expression with increasing tumour grade, no independent prognostic significance was found in this large-scale study.

Elucidating the need for prostate cancer risk calculators in conjunction with mpMRI in initial risk assessment before prostate biopsy at a tertiary prostate cancer center

OBJECTIVE

Utilizing personalized risk assessment for clinically significant prostate cancer (csPCa) incorporating multiparametric magnetic resonance imaging (mpMRI) reduces biopsies and overdiagnosis. We validated both multi- and univariate risk models in biopsy-naïve men, with and without the inclusion of mpMRI data for csPCa detection.

METHODS

N = 565 men underwent mpMRI-targeted prostate biopsy, and the diagnostic performance of risk calculators (RCs), mpMRI alone, and clinical measures were compared using receiver operating characteristic curve (ROC) analysis and decision curve analysis (DCA). Subgroups were stratified based on mpMRI findings and quality.

RESULTS

csPCa was detected in 56.3%. PI-RADS score achieved the highest area under the curve (AUC) when comparing univariate risk models (AUC 0.82, p < 0.001). Multivariate RCs showed only marginal improvement in csPCa detection compared to PI-RADS score alone, with just one of four RCs showing significant superiority. In mpMRI-negative cases, the non-MRI-based RC performed best (AUC 0.80, p = 0.016), with the potential to spare biopsies for 23%. PSA-density and multivariate RCs demonstrated comparable performance for PI-RADS 3 constellation (AUC 0.65 vs. 0.60-0.65, p > 0.5; saved biopsies 16%). In men with suspicious mpMRI, both mpMRI-based RCs and the PI-RADS score predicted csPCa excellently (AUC 0.82-0.79 vs. 0.80, p > 0.05), highlighting superior performance compared to non-MRI-based models (all p < 0.002). Quality-assured imaging consistently improved csPCa risk stratification across all subgroups.

CONCLUSION

In tertiary centers serving a high-risk population, high-quality mpMRI provides a simple yet effective way to assess the risk of csPCa. Using multivariate RCs reduces multiple biopsies, especially in mpMRI-negative and PI-RADS 3 constellation.

Key learnings from concordant systematic biopsies in prostate-specific membrane antigen positron emission tomography/computed tomography-guided prostate biopsies: Enhancing targeting accuracy

BACKGROUND

Prostate cancer (PCa) diagnosis and staging have evolved with the advent of 68Ga-Prostate-specific membrane antigen positron emission tomography/computed tomography (PSMA-PET/CT). This study investigates the role of complementary systematic biopsies (SB) during PSMA-PET/CT-guided targeted prostate biopsies (PET-TB) for PCa detection, grading, and distribution. We address the uncertainty surrounding the necessity of SB in conjunction with PET-TB.

METHODS

We analyzed PCa grading and distribution in 30 men who underwent PET-TB and SB because of contraindication to magnetic resonance imaging or high clinical suspicion of PCa. Tumor distribution was assessed in relation to the PET-highlighted lesions. Standardized reporting schemes, encompassing SUVmax , PRIMARY score, and miTNM classification, were evaluated.

RESULTS

80% of patients were diagnosed with PCa, with 70% classified as clinically significant (csPCa). SB detected more csPCa cases than PET-TB, but the differences were not statistically significant. Discordant results were observed in 25% of cases, where SB outperformed PET-TB. Spatial analysis revealed that tumor-bearing cores from SB were often located in close proximity to the PET-highlighted region. Reporting schemes showed potential for csPCa detection with significantly increased SUVmax in csPCA patients. Subsequent follow-up data underscored the importance of SB in precise PCa grading and staging.

CONCLUSIONS

While PET-TB can simplify prostate biopsy and reduce invasiveness by core number, SB cannot be omitted yet due to potential PET-TB targeting errors. Factors such as limited spatial resolution and fusion inaccuracies contribute to the need for SB. Standardization in reporting schemes currently cannot compensate for targeting errors highlighting the need for refinement.

Expression of the microtubule-associated protein 2 (MAP2) as a potential independent prognostic marker in prostate cancer

PURPOSE

Investigation of Microtubuli-associated Protein 2 (MAP2) expression and its clinical relevance in prostate cancer.

MATERIAL AND METHODS

MAP2 expression was immunohistochemically analysed on radical prostatectomy specimens using whole block sections (n = 107) and tissue microarrays (TMA; n = 310). The staining intensity was evaluated for carcinoma, benign tissue and prostatic intraepithelial neoplasia. Expression data were correlated with clinicopathological parameters and biochemical recurrence-free survival. Additionally, MAP2 protein expression was quantitatively analysed in the serum of histologically confirmed prostate carcinoma patients and the control group using a commercial enzyme-linked immunosorbent assay.

RESULTS

MAP2 staining was significantly stronger in neoplastic tissue than in non-neoplastic prostatic glands, both in whole block sections (p < 0.01) and in TMA sections (p < 0.05). TMA data revealed significantly stronger MAP2 staining in high-grade tumors. Survival analysis showed a significant correlation between strong MAP2 staining in carcinoma and shortened biochemical recurrence-free survival after prostatectomy (p < 0.001). Multivariate Cox regression analysis confirmed MAP2 as an independent predictor for an unfavourable course. Mean MAP2 serum levels for non-PCA vs. PCA patients differed significantly (non-PCA = 164.7 pg/ml vs. PCA = 242.5 pg/ml, p < 0.001).

CONCLUSION

The present data support MAP2 as a novel biomarker in PCA specimens. MAP2 is correlated with tumor grade and MAP2 high-expressing PCA is associated with an increased risk of biochemical recurrence after radical prostatectomy. Future studies are necessary to evaluate MAP2 as a valuable immunohistochemical biomarker in preoperative PCA diagnostic procedures, in particular with regard to treatment modalities.

Multiparametric Magnetic Resonance Imaging in Prostate Cancer Screening at the Age of 45 Years: Results from the First Screening Round of the PROBASE Trial

BACKGROUND

Magnetic resonance imaging (MRI) has been suggested as a tool for guiding biopsy recommendations in prostate cancer (PC) screening.

OBJECTIVE

To determine the performance of multiparametric MRI (mpMRI) in young men at age 45 yr who participated in a PC screening trial (PROBASE) on the basis of baseline prostate-specific antigen (PSA).

DESIGN, SETTING, AND PARTICIPANTS

Participants with confirmed PSA ≥3 ng/ml were offered mpMRI followed by MRI/transrectal ultrasound fusion biopsy (FBx) with targeted and systematic cores. mpMRI scans from the first screening round for men randomised to an immediate PSA test in PROBASE were evaluated by local readers and then by two reference radiologists (experience >10 000 prostate MRI examinations) blinded to the histopathology. The PROBASE trial is registered as ISRCTN37591328 OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The local and reference Prostate Imaging-Data and Reporting System (PI-RADS) scores were compared, and the sensitivity, negative predictive value (NPV), and accuracy were calculated for both readings for different cutoffs (PI-RADS 3 vs 4).

RESULTS AND LIMITATIONS

Of 186 participants, 114 underwent mpMRI and FBx. PC was detected in 47 (41%), of whom 33 (29%) had clinically significant PC (csPC; International Society of Urological Pathology grade group ≥2). Interobserver reliability between local and reference PI-RADS scores was moderate (k = 0.41). At a cutoff of PI-RADS 4, reference reading showed better performance for csPC detection (sensitivity 79%, NPV 91%, accuracy of 85%) than local reading (sensitivity 55%, NPV 80%, accuracy 68%). Reference reading did not miss any PC cases for a cutoff of PI-RADS <3. If PI-RADS ≥4 were to be used as a biopsy cutoff, mpMRI would reduce negative biopsies by 68% and avoid detection of nonsignificant PC in 71% of cases.

CONCLUSIONS

Prostate MRI in a young screening population is difficult to read. The MRI accuracy of for csPC detection is highly dependent on reader experience, and double reading might be advisable. More data are needed before MRI is included in PC screening for men at age 45 yr.

PATIENT SUMMARY

Measurement of prostate specific antigen (PSA) is an effective screening test for early detection of prostate cancer (PC) and can reduce PC-specific deaths, but it can also lead to unnecessary biopsies and treatment. Magnetic resonance imaging (MRI) after a positive PSA test has been proposed as a way to reduce the number of biopsies, with biopsy only recommended for men with suspicious MRI findings. Our results indicate that MRI accuracy is moderate for men aged 45 years but can be increased by a second reading of the images by expert radiologists. For broad application of MRI in routine screening, double reading may be advisable.

Hypermethylated SHOX2 in circulating cell-free DNA post renal cell carcinoma surgery as TNM-independent biomarker for recurrence risk

INTRODUCTION

Adjuvant immune checkpoint inhibitor trials in renal cell carcinoma (RCC) call for improved recurrence risk stratification. Due to limitations of circulating tumor DNA (ctDNA) use in RCC, the use of hypermethylated SHOX2 gene (mSHOX2) in circulating cell-free DNA is explored as a surrogate marker for identifying high-risk patients after RCC surgery.

METHODS

Liquid biopsies were collected post-surgery from 45 RCC patients (mean duration 4.3 days). Real-time polymerase chain reaction was used to analyze SHOX2 methylation in circulating cell-free DNA. Patients were categorized as mSHOX2 positive or negative by cut-off. Metastasis-free survival (MFS), cancer-specific survival (CSS), and overall survival (OS) were assessed using Cox regression and Log-rank analyses (median follow-up time: 60 months).

RESULTS

17 patients were mSHOX2 positive, showing unfavorable OS/CSS (Log-rank P = 0.004 and 0.02) and nearly 6-fold higher recurrence risk (hazard ratio 5.89, 95% CI 1.46-23.8). Multivariable Cox analysis confirmed mSHOX2 as an independent recurrence risk factor, disregarding TNM-based stratification.

CONCLUSIONS

mSHOX2 effectively identifies high-risk RCC patients post-surgery, indicating minimal residual disease. This easy to implement biomarker has potential for guiding of adjuvant therapy decisions.

Ring Finger Protein 34 (RNF34) as a Prognostic Biomarker for Clear Cell Renal Cell Carcinoma

INTRODUCTION

Ring finger proteins play pivotal roles in diverse cellular processes and are implicated in contribution to cancer. Ring finger protein 34 (RNF34) has antiapoptotic and oncogenic properties. RNF34 is upregulated during carcinogenesis and tumor progression in the colorectal adenoma-carcinoma sequence and was already described to mediate chemoresistance. In clear cell renal cell carcinoma (ccRCC), however, the role and expression patterns of RNF34 are unknown.

METHODS

First, we investigated the association of RNF34 mRNA expression with clinicopathological parameters and survival using data obtained from The Cancer Genome Atlas (TCGA) ccRCC cohort (N = 533). To assess RNA34 protein expression, we performed immunohistochemical (IHC) staining of an established ccRCC cohort (University of Bonn) in a tissue microarray (TMA) format. This validation cohort contains 109 primary ccRCC samples. IHC data were associated with clinicopathological parameters and overall survival (Kaplan-Meier analysis). Adjustment for covariables was done using the Cox regression model.

RESULTS

RNF34 expression is correlated with adverse clinicopathological parameters. Survival analysis revealed an association between RNF34 expression and shortened survival. Cox regression analysis confirmed RNF34 expression as an independent prognostic parameter.

CONCLUSION

Our study provides evidence for RNF34 as a prognostic biomarker in ccRCC and points toward a major role of this protein in renal cell carcinoma carcinogenesis.

Optimized complete cytoreduction in ovarian cancer through intraoperative real-time tumor visualization by 5-ALA - a case report

Introduction

Complete macroscopic cytoreduction represents the most important prognostic parameter for overall survival in ovarian cancer. This dogma remains tenacious despite significant improvements in adjuvant systemic treatment. Hence, optimization of surgical therapy is an overarching goal to improve patients' outcomes. In this context, intraoperative tumor-specific imaging might facilitate optimized cytoreduction. In neurosurgery, intraoperative 5-aminolevulinic acid (5-ALA) guided imaging is applied in clinical routine to assess surgical resection margins. Here, we report the case of a patient with ovarian cancer in whom intraoperative 5-ALA tumor visualization led to optimized complete cytoreduction.

Objective

Intraoperative administration of 5-ALA led to improved complete cytoreduction by identification and resection of additional ovarian cancer tumor manifestations.

Case

The 39-year-old patient, Jehovah`s witness, presented to our department with a left sided ovarian mass, suspicious of ovarian cancer, based on clinical examination, sonographic suspicious features and a CA12-5 elevation. The patient's medical history and family history was unremarkable. Preoperative CT imaging of the thorax and abdomen showed no pathology besides the adnexal mass. Surgery was performed by a midline laparotomy with hysterectomy, bilateral adnexectomy, pelvic peritonectomy, omentectomy, ureterolysis, diaphragm stripping, adhesiolysis and the collection of peritoneal and rectal samples. Intraoperative 5-ALA imaging using a dedicated excitation and detection loupe system (Reveal, DVI) led to tumor detection at the diaphragm, the omentum and the rectum that was not detectable by palpation and visualization using white light. The pathology results revealed that the 5-ALA positive samples (diaphragm, rectum and omentum) obtained by intraoperative 5-ALA were positive for ovarian cancer.

Conclusion

Intraoperative administration of 5-ALA represents a promising approach to improve complete cytoreduction in ovarian cancer surgery thereby improving clinical outcomes. Hence, further research and clinical trials are required to investigate the potential of intraoperative 5-ALA imaging in ovarian cancer debulking surgery and its impact on long-term clinical outcomes.

Digital Rectal Examination Is Not a Useful Screening Test for Prostate Cancer

BACKGROUND

Annual digital rectal examination (DRE) is recommended as a stand-alone screening test for prostate cancer (PCa) in Germany for 45+ yr olds. DRE diagnostic performance in men as young as 45 yr old has not been proved by a screening trial.

OBJECTIVE

To determine DRE diagnostic performance in a screening trial.

DESIGN, SETTING, AND PARTICIPANTS

This analysis was conducted within the multicentric, randomized PROBASE trial, which enrolled >46 000 men at age 45 to test risk-adapted prostate-specific antigen (PSA) screening for PCa.

INTERVENTION

(1) DRE was analyzed as a one-time, stand-alone screening offer at age 45 in 6537 men in one arm of the trial and (2) PCa detection by DRE was evaluated at the time of PSA-screen-driven biopsies (N = 578).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

(1) True-/false-positive detection rates of DRE as compared with PSA screening and (2) DRE outcome at the time of a prostate biopsy were evaluated.

RESULTS AND LIMITATIONS

(1) A prospective analysis of 57 men with suspicious DRE at age 45 revealed three PCa. Detection rate by DRE was 0.05% (three of 6537) as compared with a four-fold higher rate by PSA screening (48 of 23 301, 0.21%). The true-positive detection rate by DRE relative to screening by PSA was 0.22 (95% confidence interval [CI] = [0.07-0.72]) and the false-positive detection rate by DRE was 2.2 (95% CI = [1.50-3.17]). (2) Among PSA-screen-detected PCa cases, 86% had unsuspicious DRE (sensitivity relative to PSA was 14%), with the majority of these tumors (86%) located in the potentially accessible zones of the prostate as seen by magnetic resonance imaging.

CONCLUSIONS

The performance of stand-alone DRE to screen for PCa is poor. DRE should not be recommended as a PCa screening test in young men. Furthermore, DRE does not improve the detection of PSA-screen-detected PCa.

PATIENT SUMMARY

Our report demonstrated the poor diagnostic performance of digital rectal examination in the screening for prostate cancer in young men.

Web-grading-a tool to test personal grading of renal and prostate cancer

Only a few pathologists have the opportunity to verify their personal grading through objective assessment. This study introduces a web-based grading platform to facilitate and validate the grading of renal cell carcinoma and prostate cancer. Two representative images of two clinically annotated cohorts of 100 cases each of prostate and renal cell carcinoma were used. Each participant was asked to grade a tumor series utilizing a three tiered grading system. Finally, a Kaplan-Meier curve was drawn, and the log-rank test was used for statistical testing of the p-value. The grading of 22 participants (68%) achieved prognostic significance. Further analysis highlighted that only two pathologists were able to reliably separate low- and high-grade tumors from intermediate grades. The limitations of this study are the low number of participants in each of the cohorts and the potential selection bias of the tumor images. This web-based grading portal facilitates the assessment of the validity of grading by individual pathologists. The observation that most participants can only successfully identify high- or low-grade tumors but cannot discriminate between more subtle intermediate grades does indicate that there is a need for the development of more formal training programs for tumor grading.

Inflammatory fibroid polyp of the renal pelvis: first report at an extra-gastrointestinal site with molecular confirmation

Inflammatory fibroid polyps (IFP) are rare and benign mesenchymal tumours of the gastrointestinal tract. They are submucosal spindle cell lesions with an eosinophilic-rich inflammatory infiltrate and mutations in the platelet-derived growth factor receptor alpha (PDGFRA) gene. In this report, we present the case of a 74-year-old female with a solid tumour of the kidney, which presented as a bland proliferation of spindle cells with thin-walled blood vessels and an inflammatory infiltrate with eosinophilic granulocytes. Immunohistochemistry revealed a positivity for vimentin and a weak staining for CD99 and CD34 in the spindle cells. Because of the morphological similarity to IFPs of the gastrointestinal tract, a molecular pathology analysis was performed. This identified an oncogenic mutation in exon 18 of the PDGFRA gene, which is characteristic for inflammatory fibroid polyps of the gastrointestinal tract. To the best of our knowledge, this is the first case of an IFP in the urogenital tract.

Circulating Cell-Free SEPT9 DNA Methylation in Blood Is a Biomarker for Minimal Residual Disease Detection in Head and Neck Squamous Cell Carcinoma Patients

BACKGROUND

Tumorous SEPT9 (septin 9, SEPTIN9) circulating cell-free DNA (ccfDNA) methylation in blood plasma is a powerful biomarker for diagnosis, molecular staging, prognosis, and recurrence monitoring in head and neck squamous cell carcinoma (HNSCC) patients. The present study aimed to evaluate the clinical performance of SEPT9 ccfDNA methylation to detect post-surgical minimal residual disease (MRD) in patients with localized or locally advanced HNSCC treated with curative intent.

METHODS

We applied quasi-digital methylation-specific real-time PCR to quantify SEPT9 ccfDNA methylation levels 2 to 30 days post-surgically in plasma from n = 219 prospectively enrolled HNSCC patients. We tested the associations of SEPT9 ccfDNA methylation with clinicopathological parameters and used Kaplan-Meier and Cox proportional hazards analyses for univariate, pairwise bivariate, and multivariate analyses of disease-free survival.

RESULTS

Of 219 patients, 26.5% (58/219) were post-surgically SEPT9 ccfDNA methylation positive. SEPT9 ccfDNA methylation positivity was significantly associated with tumor site, American Joint Committee on Cancer/Union for International Cancer Control (AJCC/UICC; 8th edition) tumor stage, nodal category and extracapsular extension, lymphatic and vascular invasion, and surgical margin. Bivariate Cox proportional hazards analysis proved post-surgical SEPT9 ccfDNA methylation positivity to be an independent prognostic factor tested together with AJCC/UICC tumor stage (SEPT9: hazard ratio [HR] = 2.43, 95% CI, 1.37-4.30, P = 0.002; AJCC/UICC stage: HR = 1.48, 95% CI, 1.11-1.98, P = 0.008).

CONCLUSIONS

Post-surgical SEPT9 ccfDNA methylation may aid to identify high-risk HNSCC patients who could benefit from an intensified adjuvant treatment and surveillance.

CTLA4 DNA methylation is associated with CTLA-4 expression and predicts response to immunotherapy in head and neck squamous cell carcinoma

BACKGROUND

The majority of patients with recurrent or metastasized head and neck squamous cell carcinoma (HNSCC) do not benefit from immune checkpoint blockade (ICB) while several patients experience severe and persistent immune-mediated side effects. Therefore, predictive biomarkers are urgently needed to allow for a personalized treatment. In this study, we investigated DNA methylation of the immune checkpoint gene CTLA4 with regard to its predictive value.

METHODS

We analyzed CTLA4 promoter methylation in tumors of HNSCC patients (N = 29) treated with ICB at the University Medical Center Bonn with regard to response to ICB and progression-free survival. We further analyzed a second cohort (N = 138) of patients that did not receive ICB with regard to CTLA4 promoter methylation, CTLA-4 protein expression, and immune cell infiltrates. Finally, we tested inducibility of CTLA-4 protein expression in HNSCC cells using the DNA methyltransferase inhibitor decitabine.

RESULTS

Lower CTLA4 promoter methylation correlated with response to ICB and prolonged progression-free survival. We could show that not only tumor infiltrating immune cells, but also HNSCC cells harbor cytoplasmic and nuclear CTLA-4 expression. CTLA4 promoter methylation inversely correlated with infiltrates of CD3+, CD4+, CD8+, and CD45+ immune cells. CTLA4 methylation did not correlate with protein expression in tumors, however, decitabine treatment led to decreased CTLA4 methylation and an induction of CTLA4 mRNA and CTLA-4 protein expression in HNSCC cell lines.

CONCLUSIONS

Our results indicate that CTLA4 DNA hypomethylation is a predictive biomarker for response to ICB in HNSCC. Our study warrants further analyses of the predictive value of CTLA4 DNA methylation in clinical trials of anti-PD-1 and/or anti-CTLA-4 immunotherapy in HNSCC.

ICOS DNA methylation regulates melanoma cell-intrinsic ICOS expression, is associated with melanoma differentiation, prognosis, and predicts response to immune checkpoint blockade

BACKGROUND

Inducible T cell costimulator ICOS is an emerging target in immuno-oncology. The aim of this study was to investigate the epigenetic regulation of ICOS in melanoma by DNA methylation.

METHODS

We comprehensively investigate ICOS DNA methylation of specific CpG sites and expression pattern within the melanoma microenvironment with regard to immune correlates, differentiation, clinical outcomes, and immune checkpoint blockade (ICB) response.

RESULTS

Our study revealed a sequence-contextual CpG methylation pattern consistent with an epigenetically regulated gene. We found a cell type-specific methylation pattern and locus-specific correlations and associations of CpG methylation with ICOS mRNA expression, immune infiltration, melanoma differentiation, prognosis, and response to ICB. High ICOS mRNA expression was identified as a surrogate for enriched immune cell infiltration and was associated with favorable overall survival (OS) in non-ICB-treated patients and predicted response and a prolonged progression-free survival (PFS) following ICB therapy initiation. ICOS hypomethylation, however, significantly correlated with poor OS in non-ICB patients but predicted higher response and prolonged PFS and OS in ICB-treated patients. Moreover, we observed cytoplasmic and sporadically nuclear tumor cell-intrinsic ICOS protein expression. Tumor cell-intrinsic ICOS protein and mRNA expression was inducible by pharmacological demethylation with decitabine.

CONCLUSION

Our study identified ICOS DNA methylation and mRNA expression as promising prognostic and predictive biomarkers for immunotherapy in melanoma and points towards a hitherto undescribed role of ICOS in tumor cells.

Endogenous myoglobin expression in mouse models of mammary carcinoma reduces hypoxia and metastasis in PyMT mice

Myoglobin (MB) is expressed in different cancer types and may act as a tumor suppressor in breast cancer. The mechanisms by which basal MB expression level impacts murine mammary tumorigenesis are unclear. We investigated how MB expression in breast cancer influences proliferation, metastasis, tumor hypoxia, and chemotherapy treatment in vivo. We crossed PyMT and WapCreTrp53^flox mammary cancer mouse models that differed in tumor grade/type and onset of mammary carcinoma with MB knockout mice. The loss of MB in WapCre;Trp53^flox mice did not affect tumor development and progression. On the other hand, loss of MB decreased tumor growth and increased tissue hypoxia as well as the number of lung metastases in PyMT mice. Furthermore, Doxorubicin therapy prevented the stronger metastatic propensity of MB-deficient tumors in PyMT mice. This suggests that, although MB expression predicts improved prognosis in breast cancer patients, MB-deficient tumors may still respond well to first-line therapies. We propose that determining the expression level of MB in malignant breast cancer biopsies will improve tumor stratification, outcome prediction, and personalized therapy in cancer patients.

TROP-2 is widely expressed in vulvar squamous cell carcinoma and represents a potential new therapeutic target

PURPOSE

Vulvar squamous cell carcinoma (VSCC) is a rare malignancy of the female genital tract with increasing incidence rates. Etiologically, HPV-dependent and HPV-independent VSCC are distinguished. Surgical treatment and/or radiotherapy represent the therapeutic mainstay for localized disease. For recurrent or metastatic VSCC, treatment options are limited. Research has identified trophoblast cell surface antigen 2 (TROP-2) to be broadly expressed across different tumor entities. The aim of the present study was to systematically investigate the expression of TROP-2 in VSCC.

METHODS

TROP-2 protein expression was investigated by immunohistochemistry in a cohort comprising n = 103 patients with primary VSCC. A four-tier scoring system (0: no staining, 1 + : low staining, 2 + : moderate staining, 3 + : high staining) was applied for quantification of protein expression. For further analyses, two groups (low TROP-2 expression: 0/1 + ; high TROP-2 expression: 2 + /3 +) were generated. The entire study cohort, as well as HPV-dependent and HPV-independent VSCC were considered separately.

RESULTS

In the entire VSCC study cohort, TROP-2 expression was present in 97.1% of all cases (n = 100) with 74.8% displaying high TROP-2 expression (2 + /3 +). Only 2.9% of tumors showed absent TROP-2 expression. Of note, all HPV-dependent VSCC (n = 18) demonstrated high TROP-2 expression (2 + /3 +). In the subgroup of HPV-independent VSCC (n = 70), high TROP-2 expression was associated with favorable clinical outcomes based on log rank test and univariate cox analysis.

CONCLUSION

TROP-2 protein expression is of prognostic value in HPV-independent VSCC. The broad expression of TROP-2 in VSCC indicates the TROP-2 directed ADC Sacituzumab govitecan as a potential new therapeutic strategy for VSCC patients.

Abstract 3963: Mass spectrometry reveals a downregulation of calreticulin after neoadjuvant chemotherapy in pancreatic cancer

Introduction: Pancreatic ductal adenocarcinomas are one of the deadliest cancer types with limited response to current therapies. Thus, this study examined changes in the proteome of epithelial cells in pancreatic cancer after neoadjuvant chemotherapy with gemcitabine, to identify new therapeutic targets.

Methods: Upon receiving patient consent, fresh pancreatic cancer tissue was received from surgical tumor resections at the University Hospital of Bonn. We mechanically and enzymatically digested and purified the tissue to create single-cell suspensions. After staining the cells against CD45 und CD326, we purified epithelial cells, blood cells, and stroma through FACS. To analyze their proteome, the sorted cells were lysed in TEAB buffer and the protein lysates were measured by the mass spectrometry core facility at the University of Bonn. We then analyzed the data using DAVID and Shiny GO.

Results: Gene enrichment analyses showed a significantly reduced expression of calreticulin after neoadjuvant chemotherapy in epithelial cells. A direct comparison between untreated and treated epithelium cancer cells using a heat map showed a decreased expression of actin and enzymes of glycolysis in treated cancer cells. Moreover, untreated epithelial cells showed an increase of proteins related to MHC class Ib protein complex assembly and antigen processing and presentation of endogenous peptide antigen via MHC class. In contrast, treated cells showed a higher presence of proteins for nutrient supply from the blood. Furthermore, untreated stroma cells exhibited an increased number of proteins responsible for mesenchymal migration and for actin filament fragmentation.

Conclusion: This study shows that neoadjuvant chemotherapy with gemcitabine leads to distinct changes in the proteome of tumor cells in pancreatic cancers. In particular, a decreased expression of the “eat-me-signal” calreticulin impairs macrophage-mediated cancer cell phagocytosis, thereby indicating a mechanism by which cancer cells protect themselves after chemotherapy.

Citation Format: Michael C. Stoffel, Elisabeth BH Dingendorf, Dahlia L. Kittel, Glen Kristiansen, Tristan Lerbs. Mass spectrometry reveals a downregulation of calreticulin after neoadjuvant chemotherapy in pancreatic cancer. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3963.

Identification of F-Box/SPRY Domain-Containing Protein 1 (FBXO45) as a Prognostic Biomarker for TMPRSS2-ERG-Positive Primary Prostate Cancers

BACKGROUND

F-box/SPRY domain-containing protein 1 (FBXO45) plays a crucial role in the regulation of apoptosis via the ubiquitylation and degradation of specific targets. Recent studies indicate the prognostic potential of FBXO45 in several cancers. However, its specific role in prostate carcinoma remains unclear.

METHODS

A systematic analysis of FBXO45 mRNA expression in PCA was performed using The Cancer Genome Atlas database and a publicly available Gene Expression Omnibus progression PCA cohort. Subsequently, FBXO45 protein expression was assessed via immunohistochemical analysis of a comprehensive tissue microarray cohort. The expression data were correlated with the clinicopathological parameters and biochemical-free survival. The immunohistochemical analyses were stratified according to the TMPRSS2-ERG rearrangement status. To assess the impact of FBXO45 knockdown on the tumour proliferation capacity of cells and metastatic potential, transfection with antisense-oligonucleotides was conducted within a cell culture model.

RESULTS

FBXO45 mRNA expression was associated with adverse clinicopathological parameters in the TCGA cohort and was enhanced throughout progression to distant metastasis. FBXO45 was associated with shortened biochemical-free survival, which was pronounced for the TMPRSS2-ERG-positive tumours. In vitro, FBXO45 knockdown led to a significant reduction in migration capacity in the PC3, DU145 and LNCaP cell cultures.

CONCLUSIONS

Comprehensive expression analysis and functional data suggest FBXO45 as a prognostic biomarker in PCA.

DEPROMP Trial: the additive value of PSMA-PET/CT-guided biopsy for prostate cancer management in biopsy naïve men-study protocol for a randomized trial

BACKGROUND

The primary objective is to determine the proportion of men with suspected prostate cancer (PCA) in whom the management plans are changed by additive gallium-68 prostate-specific membrane antigen positron emission tomography/computed tomography (PSMA-PET/CT) guided prostate biopsy (PET-TB) in combination with standard of care (SOC) using systematic (SB) and multiparametric magnetic resonance imaging-guided biopsy (MR-TB) compared with SOC alone. The major secondary objectives are to determine the additive value of the combined approach of SB + MR-TB + PET-TB (PET/MR-TB) for detecting clinically significant PCA (csPCA) compared to SOC; to determine sensitivity, specificity, positive and negative predictive value and diagnostic accuracy of imaging techniques, respective imaging classification systems, and each biopsy method; and to compare preoperatively defined tumor burden and biomarker expression and pathological tumor extent in prostate specimens.

METHODS

The DEPROMP study is a prospective, open-label, interventional investigator-initiated trial. Risk stratification and management plans after PET/MR-TB are conducted randomized and blinded by different evaluation teams of experienced urologists based on histopathological analysis and imaging information: one including all results of the PET/MR-TB and one excluding the additional information gained by PSMA-PET/CT guided biopsy. The power calculation was centered on pilot data, and we will recruit up to 230 biopsy-naïve men who will undergo PET/MR-TB for suspected PCA. Conduct and reporting of MRI and PSMA-PET/CT will be performed in a blinded fashion.

DISCUSSION

The DEPROMP Trial will be the first to evaluate the clinically relevant effects of the use of PSMA-PET/CT in patients with suspected PCA compared to current SOC. The study will provide prospective data to determine the diagnostic yields of additional PET-TB in men with suspected PCA and the impact on treatment plans in terms of intra- and intermodal changes. The results will allow a comparative analysis of risk stratification by each biopsy method, including a performance analysis of the corresponding rating systems. This will reveal potential intermethod and pre- and postoperative discordances of tumor stage and grading, providing the opportunity to critically assess the need for multiple biopsies.

TRIAL REGISTRATION

German Clinical Study Register DRKS 00024134. Registered on 26 January 2021.

Adherence to a risk-adapted screening strategy for prostate cancer: First results of the PROBASE trial

PROBASE is a population-based, randomized trial of 46 495 German men recruited at age 45 to compare effects of risk-adapted prostate cancer (PCa) screening starting either immediately at age 45, or at a deferred age of 50 years. Based on prostate-specific antigen (PSA) levels, men are classified into risk groups with different screening intervals: low-risk (<1.5 ng/ml, 5-yearly screening), intermediate-risk (1.5-2.99 ng/ml, 2 yearly), and high risk (>3 ng/ml, recommendation for immediate biopsy). Over the first 6 years of study participation, attendance rates to scheduled screening visits varied from 70.5% to 79.4%, depending on the study arm and risk group allocation, in addition 11.2% to 25.4% of men reported self-initiated PSA tests outside the PROBASE protocol. 38.5% of participants had a history of digital rectal examination or PSA testing prior to recruitment to PROBASE, frequently associated with family history of PCa. These men showed higher rates (33% to 57%, depending on subgroups) of self-initiated PSA testing in-between PROBASE screening rounds. In the high-risk groups (both arms), the biopsy acceptance rate was 64% overall, but was higher among men with screening PSA ≥4 ng/ml (>71%) and with PIRADS ≥3 findings upon multiparameter magnetic resonance imaging (mpMRI) (>72%), compared with men with PSA ≥3 to 4 ng/ml (57%) or PIRADS score ≤ 2 (59%). Overall, PROBASE shows good acceptance of a risk-adapted PCa screening strategy in Germany. Implementation of such a strategy should be accompanied by a well-structured communication, to explain not only the benefits but also the harms of PSA screening.

Bi-allelic loss-of-function variants in KIF21A cause severe fetal akinesia with arthrogryposis multiplex

BACKGROUND

Fetal akinesia (FA) results in variable clinical presentations and has been associated with more than 166 different disease loci. However, the underlying molecular cause remains unclear in many individuals. We aimed to further define the set of genes involved.

METHODS

We performed in-depth clinical characterisation and exome sequencing on a cohort of 23 FA index cases sharing arthrogryposis as a common feature.

RESULTS

We identified likely pathogenic or pathogenic variants in 12 different established disease genes explaining the disease phenotype in 13 index cases and report 12 novel variants. In the unsolved families, a search for recessive-type variants affecting the same gene was performed; and in five affected fetuses of two unrelated families, a homozygous loss-of-function variant in the kinesin family member 21A gene (KIF21A) was found.

CONCLUSION

Our study underlines the broad locus heterogeneity of FA with well-established and atypical genotype-phenotype associations. We describe KIF21A as a new factor implicated in the pathogenesis of severe neurogenic FA sequence with arthrogryposis of multiple joints, pulmonary hypoplasia and facial dysmorphisms. This hypothesis is further corroborated by a recent report on overlapping phenotypes observed in Kif21a null piglets.

Current role of systematic biopsy in diagnosis of clinically significant prostate cancer in primary combined MRI-targeted biopsy: a high-volume single-center study

PURPOSE

Additive systematic biopsy (SB) contributes to prostate cancer (PCA) detection in MRI-targeted biopsy (TB). However, the reasons for this are not yet clear. We compared the performance of TB, SB and the combined approach (CB) in biopsy-naive men to determine the added value of SB for tumor grading and spatial tumor distribution.

METHODS

Two hundred and fifty-nine men with PI-RADS 3-5 graded lesions who underwent CB were enrolled. Data were prospectively collected, and cancer detection rates (CDR) were compared at patient and lesion level. Gleason grade up- and down-grading from biopsy to prostatectomy specimens (n = 56; 21.6%) were determined. Clinically significant cancer (csPCA) was defined as Gleason grade ≥ 2.

RESULTS

CDR by CB based on PI-RADS categories 3, 4 and 5 for PCA were 24%, 72% and 98% and 17%, 64% and 96% for csPCA. CB detected more PCA and csPCA than TB (p < 0.001). However, TB showed higher efficiency, defined as CDR per biopsy core, for PCA and csPCA in PI-RADS 4-5 rated patients (p < 0.001). Concordance between biopsy and prostatectomy grading was highest in CB with misdiagnosis of csPCA in 25% of men. TB missed cancer attributed to the index lesion in 10.2% and underestimated csPCA in 7%. In these cases, 76% of csPCA were detected and 85% were upgraded to csPCA by SB in adjacent sectors.

CONCLUSION

SB cannot be safely abundant without increased diagnostic uncertainty. When TB missed csPCA, SB detected it close to the MRI-target lesion. Therefore, perifocal biopsies could potentially replace 12-core SB with increased efficiency in taking manageable risks.

Real-time use of artificial intelligence (CADEYE) in colorectal cancer surveillance of patients with Lynch syndrome-A randomized controlled pilot trial (CADLY)

BACKGROUND

Lynch syndrome (LS), an autosomal dominant disorder caused by pathogenic germline variants in DNA mismatch repair (MMR) genes, represents the most common hereditary colorectal cancer (CRC) syndrome. Lynch syndrome patients are at high risk of CRC despite regular endoscopic surveillance.

OBJECTIVE

Our aim was to investigate the diagnostic performance of artificial intelligence (AI)-assisted colonoscopy in comparison to High-Definition white-light endoscopy (HD-WLE) for the first time.

METHODS

Patients ≥18 years with LS, with a pathogenic germline variant (MLH1, MHS2, MSH6), and at least one previous colonoscopy (interval 10-36 months) were eligible. Patients were stratified by previous CRC and affected MMR gene with a 1:1 allocation ratio (AI-assisted vs. HD white-light endoscopy) in this exploratory pilot trial.

RESULTS

Between Dec-2021 and Dec-2022, 101 LS patients were randomised and 96 patients were finally analyzed after exclusion of 5 patients due to insufficient bowel preparation. In the HD-WLE arm, adenomas were detected in 12/46 patients compared to 18/50 in the AI arm (26.1% [95% CI 14.3-41.1] vs. 36.0% [22.9-50.8]; p = 0.379). The use of AI-assisted colonoscopy especially increased detection of flat adenomas (Paris classification 0-IIb) (examinations with detected flat adenomas: 3/46 [6.5%] vs. 10/50 [20%]; p = 0.07; numbers of detected flat adenomas: 4/20 vs. 17/30, p = 0.018). The median withdrawal time did not differ significantly between HD-WLE and AI (14 vs. 15 min; p = 0.170).

CONCLUSION

We here present first data suggesting that real-time AI-assisted colonoscopy is a promising approach to optimize endoscopic surveillance in LS patients, in particular to improve the detection of flat adenomas.

Membranous NECTIN-4 expression frequently decreases during metastatic spread of urothelial carcinoma and is associated with enfortumab vedotin resistance

Background: The antibody-drug conjugate enfortumab vedotin (EV) releases a cytotoxic agent into tumor cells via binding to the membrane receptor NECTIN-4. EV has been recently approved for patients with metastatic urothelial carcinoma (mUC) without prior assessment of the tumor receptor status as ubiquitous NECTIN-4 expression is assumed. Objective: To determine the prevalence of membranous NECTIN-4 protein expression in primary tumors (PRIM) and patient-matched distant metastases (MET). Main Outcomes and Measures: Membranous NECTIN-4 protein expression was measured (H-score) by immunohistochemistry (IHC) in PRIM and corresponding MET (N=137) and in a multicenter EV-treated cohort (N=47). Progression-free survival (PFS) after initiation of EV treatment was assessed for the NECTIN-4 negative/weak (H-score 0-99) versus moderate/strong (H-score 100-300) subgroup. The specificity of the NECTIN-4 IHC staining protocol was validated by establishing CRISPR-Cas9-induced polyclonal NECTIN-4 knockouts. Results: In our cohort, membranous NECTIN-4 expression significantly decreased during metastatic spread (Wilcoxon matched pairs P&lt;0.001, median H-score=40, interquartile range (IQR): 0-140), with 39.4% of MET lacking membranous NECTIN-4 expression. In our multicenter EV cohort, absence or weak membranous NECTIN-4 expression (34.0% of the cohort) was associated with a significantly shortened PFS on EV (Log-rank P&lt;0.001). Conclusion: Membranous NECTIN-4 expression is frequently decreased or absent in mUC tissue. Of note, the clinical benefit of EV strongly depends on membranous NECTIN-4 expression. Thus, our results are of highest clinical relevance and argue for a critical reconsideration of the current practice and suggest that the NECTIN-4 receptor status should be determined (ideally in a metastatic/ progressive lesion) before initiation of EV.

Nectin-4 is widely expressed in head and neck squamous cell carcinoma

Purpose: Nectin-4 has been successfully established as a target molecule in locally advanced and metastatic bladder cancer. An antibody-drug conjugate (enfortumab-vedotin) directed against nectin-4 has shown marked tumor remission rates in this tumor type, which is known for high expression rates of nectin-4. As head and neck cancer and urothelial carcinomas share morphological and molecular similarities, we aimed to evaluate Nectin-4 expression in head and neck squamous cell carcinoma (HNSCC).

Material and Methods: A previously described and clinically characterized cohort of HNSCC (n = 159) was analyzed by immunohistochemistry for Nectin-4 expression. The expression data was correlated to clinico-pathological parameters including patient outcome.

Results: Nectin-4 was found in 86.2% of HNSCC, with medium/high expression seen in 32.7% of cases. Non smokers and p16 positive HNSCC showed a higher expression of Nectin-4 (p < 0.005). There was no correlation of Nectin-4 with grading or tumor stage. Nectin-4 positive tumors showed a significant better survival (log rank p = 0.006).

Conclusions: Similar to urothelial carcinoma, Nectin-4 is found in the majority of HNSCC, which clearly warrants further studies to clarify if HNSCC also respond to targeted therapy with enfortumab-vedotin. Moreover, expression of Nectin-4 is associated with HPV infection and may serve as a prognostic marker in HNSCC.

Myoglobin regulates fatty acid trafficking and lipid metabolism in mammary epithelial cells

Myoglobin (MB) is known to bind and deliver oxygen in striated muscles at high expression levels. MB is also expressed at much reduced levels in mammary epithelial cells, where the protein´s function is unclear. In this study, we aim to determine whether MB impacts fatty acid trafficking and facilitates aerobic fatty acid ß-oxidation in mammary epithelial cells. We utilized MB-wildtype versus MB-knockout mice and human breast cancer cells to examine the impact of MB and its oxygenation status on fatty acid metabolism in mouse milk and mammary epithelia. MB deficient cells were generated through CRISPR/Cas9 and TALEN approaches and exposed to various oxygen tensions. Fatty acid profiling of milk and cell extracts were performed along with cell labelling and immunocytochemistry. Our findings show that MB expression in mammary epithelial cells promoted fatty acid oxidation while reducing stearyl-CoA desaturase activity for lipogenesis. In cells and milk product, presence of oxygenated MB significantly elevated indices of limited fatty acid ß-oxidation, i.e., the organelle-bound removal of a C2 moiety from long-chain saturated or monounsaturated fatty acids, thus shifting the composition toward more saturated and shorter fatty acid species. Presence of the globin also increased cytoplasmic fatty acid solubility under normoxia and fatty acid deposition to lipid droplets under severe hypoxia. We conclude that MB can function in mammary epithelia as intracellular O2-dependent shuttle of oxidizable fatty acid substrates. MB's impact on limited oxidation of fatty acids could generate inflammatory mediator lipokines, such as 7-hexadecenoate. Thus, the novel functions of MB in breast epithelia described herein range from controlling fatty acid turnover and homeostasis to influencing inflammatory signalling cascade. Future work is needed to analyse to what extent these novel roles of MB also apply to myocytic cell physiology and malignant cell behaviour, respectively.

Addition of Chromosome 17 Polysomy and HER2 Amplification Status Improves the Accuracy of Clinicopathological Factor-Based Progression Risk Stratification and Tumor Grading of Non-Muscle-Invasive Bladder Cancer

Progression of non-muscle-invasive bladder cancer (NMIBC) to muscle-invasive disease (MIBC) significantly worsens life expectancy. Its risk can be assessed by clinicopathological factors according to international guidelines. However, additional molecular markers are needed to refine and improve the prediction. Therefore, in the present study, we aimed to predict the progression of NMIBCs to MIBC by assessing p53 expression, polysomy of chromosome 17 (Chr17) and HER2 status in the tissue specimens of the tumors of 90 NMIBC patients. Median follow-up was 77 months (range 2−158). Patients with Chr17 polysomy or HER2 gene amplification had a higher rate of disease progression (hazard ratio: 7.44; p < 0.001 and 4.04; p = 0.033, respectively; univariate Cox regression). Multivariable Cox regression models demonstrated that the addition of either Chr17 polysomy or HER2 gene amplification status to the European Association of Urology (EAU) progression risk score increases the c-index (from 0.741/EAU/ to 0.793 and 0.755, respectively), indicating that Chr17 polysomy/HER2 amplification status information improves the accuracy of the EAU risk table in predicting disease progression. HER2/Chr17 in situ hybridization can be used to select non-progressive cases not requiring strict follow-up, by reclassifying non-HER2-amplified, non-polysomic NMIBCs from the high- and very high-risk groups of EAU to the intermediate-risk group.

Early Dynamics of Quantitative SEPT9 and SHOX2 Methylation in Circulating Cell-Free Plasma DNA during Prostate Biopsy for Prostate Cancer Diagnosis

Background: The methylation status of Septin 9 (SEPT9) and short stature homeobox 2 (SHOX2) in circulating cell-free DNA (ccfDNA) are validated pan-cancer biomarkers. The present proof-of-concept study aimed to investigate the potential and dynamics of quantitative SEPT9 and SHOX2 methylation in prostate cancer (PCa) patient tissue and ccfDNA during prostate biopsy as a diagnostic tool. Methods: The methylation patterns of SEPT9 and SHOX2 in prostate tissue were analyzed using The Cancer Genome Atlas data set (n = 498 PCa and n = 50 normal adjacent prostate tissue (NAT)). Next, dynamic changes of ccfDNA methylation were quantified in prospectively enrolled patients undergoing prostate biopsy (n = 72), local treatment for PCa (n = 7; radical prostatectomy and radiotherapy) as well as systemic treatment for PCa (n = 6; chemotherapy and 177-Lu-PSMA-therapy). Biomarker levels were correlated with clinicopathological parameters. Results: SEPT9 and SHOX2 were hypermethylated in PCa tissue (p < 0.001) and allowed discrimination of PCa and non-tumor prostate tissue (mSEPT9: AUC 0.87, 95%CI [0.82−0.92]; mSHOX2: AUC 0.89, 95%CI 0.84−0.94). SHOX2 methylation and mRNA levels were significantly higher in PCa tissue and increased with tumor stage and grade, as well as in patients suffering from biochemical recurrence following radical prostatectomy. SEPT9 and SHOX2 ccfDNA methylation allowed distinguishing patients with localized and metastatic disease (p < 0.001 for both). In addition, methylation levels increased shortly after prostate biopsy only in patients with PCa (ΔmSEPT9: p < 0.001 and ΔmSHOX2: p = 0.001). Conclusions: The early dynamics of methylated SEPT9 and SHOX2 in ccfDNA allow differentiation between PCa patients and patients without PCa and is a promising marker for tumor monitoring in the metastatic stage to determine tumor burden under systemic therapy.

N6-methyladenosine RNA modification (m6A) is of prognostic value in HPV-dependent vulvar squamous cell carcinoma

Background

Vulvar squamous cell carcinoma (VSCC) is an uncommon gynecologic malignancy but with an increasing incidence in recent years. Etiologically, VSCC is classified into two subtypes: HPV-dependent and HPV-independent. Localized VSCC is treated surgically and/or with radiation therapy, but for advanced, metastatic or recurrent disease, therapeutic options are still limited.

N6-methyladenosine (m6A) is the most prevalent post-transcriptional messenger RNA (mRNA) modification and involved in many physiological processes. The group of m6A proteins can be further divided into: ‚writers’ (METTL3, METTL4, METTL14, WTAP, KIAA1429), ‚erasers’ (FTO, ALKBH5), and ‚readers’ (HNRNPA2B1, HNRNPC, YTHDC1, YTHDF1-3). Dysregulated m6A modification is implicated in carcinogenesis, progression, metastatic spread, and drug resistance across various cancer entities. Up to date, however, only little is known regarding the role of m6A in VSCC.

Methods

Here, we comprehensively investigated protein expression levels of a diverse set of m6A writers, readers and erasers by applying immunohistochemical staining in 126 patients with primary VSCC.

Results

In the entire study cohort, dominated by HPV-independent tumors, m6A protein expression was not associated with clinical outcome. However, we identified enhanced protein expression levels of the ‚writers’ METTL3, METTL14 and the ‚reader’ YTHDC1 as poor prognostic markers in the 23 patients with HPV-dependent VSCC.

Conclusion

Our study suggests dysregulated m6A modification in HPV-associated VSCC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-10010-x.

Anti-CD40 predominates over anti-CTLA-4 to provide enhanced antitumor response of DC-CIK cells in renal cell carcinoma

Cytokine-induced killer cells (CIK) in combination with dendritic cells (DCs) have shown favorable outcomes in renal cell carcinoma (RCC), yet some patients exhibit recurrence or no response to this therapy. In a broader perspective, enhancing the antitumor response of DC-CIK cells may help to address this issue. Considering this, herein, we investigated the effect of anti-CD40 and anti-CTLA-4 antibodies on the antitumor response of DC-CIK cells against RCC cell lines. Our analysis showed that, a) anti-CD40 antibody (G28.5) increased the CD3+CD56+ effector cells of CIK cells by promoting the maturation and activation of DCs, b) G28.5 also increased CTLA-4 expression in CIK cells via DCs, but the increase could be hindered by the CTLA-4 inhibitor (ipilimumab), c) adding ipilimumab was also able to significantly increase the proportion of CD3+CD56+ cells in DC-CIK cells, d) anti-CD40 antibodies predominated over anti-CTLA-4 antibodies for cytotoxicity, apoptotic effect and IFN-γ secretion of DC-CIK cells against RCC cells, e) after ipilimumab treatment, the population of Tregs in CIK cells remained unaffected, but ipilimumab combined with G28.5 significantly reduced the expression of CD28 in CIK cells. Taken together, we suggest that the agonistic anti-CD40 antibody rather than CTLA-4 inhibitor may improve the antitumor response of DC-CIK cells, particularly in RCC. In addition, we pointed towards the yet to be known contribution of CD28 in the crosstalk between anti-CTLA-4 and CIK cells.

Comprehensive immunohistochemical analysis of N6-methyladenosine (m6A) writers, erasers, and readers in endometrial cancer

PURPOSE

N6-methyladenosine (m6A) is the most frequent type of messenger RNA (mRNA) modification and is implicated in diverse physiological processes. The procedure of m6A RNA modification is regulated by a dynamic interaction of writers (METTL3, METTL4, METTL14, WTAP, KIAA1429), erasers (FTO, ALKBH5), and readers (HNRNPA2B1, HNRNPC, YTHDC1, YTHDC1, YTHDF1-3). In the oncological context, alterations in m6A were identified to be critically involved in tumorigenesis, proliferation, angiogenesis, and drug resistance across diverse cancer entities including endometrial cancer (EC).

METHODS

In this study, we comprehensively examined the protein expression of m6A writers, readers and erasers by immunohistochemical staining in a cohort of N = 65 EC patients. Protein expression data were analyzed with regard to clinical outcomes.

RESULTS

We identified enhanced protein expression levels of METTL3, METTL14, FTO, HNRNPA2B1, and HNRNPC, respectively to be of prognostic value and linked to a shortened overall survival in EC.

CONCLUSION

Overall, our study points toward dysregulated m6A modification in EC and its possibility to serve as a promising prognostic biomarker.

Abstract 831: Discovery of a novel soluble Neuropilin-2 isoform with antiangiogenic and antitumorigenic activity

Upregulation of the non-tyrosine kinase receptor neuropilin-2 (NRP2) is described for several tumor entities and correlates with disease progression. Two membrane-anchored isoforms are transcribed from the NRP2 gene that only differ in their terminal exons to encode transmembrane stretches and short cytoplasmic tails, respectively. While NRP2a was shown to support tumor cell proliferation, NRP2b facilitates tumor cell migration, resulting in enhanced metastatic spreading. A third, soluble NRP2 isoform encoding only aminoterminal protein domains exists as dimeric protein and functions in sequestration of the VEGF-C ligand. By using a next-generation sequencing approach to enrich for NRP2 terminal exons, we identified NRP2-Mo83, a novel NRP2 isoform, from a high expressing tumor cell line, and verified secreted NRP2-Mo83 protein by mass spectrometry in cell supernatants. Preliminary mass spectrometric data give an indication of the presence of soluble NRP2-Mo83 protein in human serum samples.NRP2-Mo83 mRNA is expressed at variable quantities in vitro in a panel of bladder carcinoma cell lines, but is downregulated in a small cohort of macrodissected urothelial carcinoma samples. Transcript abundances of a NRP2 transcript classified as non-coding with high sequence similarity to the NRP2-Mo83 3’ terminus confirm the observed downregulation in the TCGA bladder carcinoma cohort.Preliminary data indicate that recombinant NRP2-Mo83 protein exerts a dose-dependent inhibitory effect on tumor cell growth in vitro in all tested bladder carcinoma cell lines in the presence of serum. However, a fraction of cell lines does not respond to NRP2-Mo83 under serum-starved conditions. Proliferation of human endothelial cells (HUVEC) is inhibited in a dose-dependent manner by recombinant NRP2-Mo83 protein in vitro. In vivo, NRP2-Mo83 reveals an anti-angiogenic effect on the chicken chorioallantoic membrane.Recombinant NRP2-Mo83 is secreted by HEK293 cells. Enrichment of endogenous and purification of recombinant NRP2-Mo83 protein is achieved by exploiting its capacity to bind heparin. In contrast to the described s9NRP2 isoform, NRP2-Mo83 is largely monomeric in solution, as verified by size exclusion chromatography. We identified N and O glycosylation as well as the capacity for polysialation as posttranslational modifications of recombinant NRP2-Mo83 protein, similar to membrane anchored NRP2 isoforms. NanoDSF experiments indicate that calcium ions stabilize NRP2-Mo83. We present NRP2-Mo83 as a novel NRP2 splice isoform, validated its expression at the mRNA and protein level. NRP2-Mo83 appears down-regulated during bladder tumorigenesis, congruent with its function in bladder tumor growth inhibition and its anti-angiogenic properties in vitro and in vivo. The identification of NRP2-Mo83 in human serum may suggest a suppressive function even under non-pathological conditions.

Citation Format: Thomas Mayr, Paul L. Dix, Sayed-Mohammad Hasheminasab, Chuanpit Hampel, Marc Sylvester, Niels Schneberger, Sarah Foerster, Gregor Hagelueken, Samikshan Dutta, Glen Kristiansen, Regine Schneider-Stock, Kaustubh Datta, Michael H. Muders. Discovery of a novel soluble Neuropilin-2 isoform with antiangiogenic and antitumorigenic activity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 831.

Abstract 521: The role of the E3 ubiquitin ligase Parkin in clear cell renal cell carcinoma

Introduction: The E3 ubiquitin ligase Parkin has been described in several cancer entities, including clear cell renal cell carcinoma (ccRCC). Decreased Parkin expression is associated with poor prognosis. We aimed to clarify the biological role of Parkin in ccRCC and to evaluate its expression in a clinically characterized renal cancer cohort.

Methods: We analyzed cell lines and clinically annotated patient material with qPCR (n=63), immunohistochemistry (n=262), LC-mass spectrometry and performed functional analyses in cell line models.

Results: We found that overexpression of Parkin results in a less aggressive phenotype in the clear cell renal cell carcinoma cell line 786-O indicated by lower migration and invasion. Mass spectrometry revealed decreased levels of several proteins in Parkin expressing cells. One of these proteins was cyclin kinase subunit 2 (CKS2). The introduction of a C431S mutation in the catalytic domain of the Parkin gene abolished the effect of decreased migration. In addition, knockdown of CKS2 in cells lacking Parkin caused decreased migration suggesting that the effect of Parkin is CKS2 mediated. Furthermore, the correlation of CKS2 and tumor grading is highly significant and high levels of CKS2 are associated with shorter survival times.

Conclusions: Parkin plays a major role in ccRCC biology, regulation cell migration and invasion, possibly exerted by CKS2 signaling. In consequence CKS2 appears to be an interesting prognostic biomarker in clear cell renal cell carcinoma and might also serve as a new therapy target.

Citation Format: Laura Kristin Esser, Vittorio Branchi, Farhad Shaker, Adrian Georg Simon, Carsten Stephan, Glen Kristiansen, Andreas Buness, Hubert Schorle, Marieta I. Toma. The role of the E3 ubiquitin ligase Parkin in clear cell renal cell carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 521.

HGG-21. Oncogenic tyrosine kinase gene fusions in infant-type hemispheric gliomas - comparison of RNA- and DNA-based methods for their reliable detection

High-grade diffuse gliomas (HGG) in early childhood are characterized by a more favorable outcome compared to older children. We demonstrated in previous studies that these tumors have stable genomes. Activating tyrosine kinase gene fusions in infant-type hemispheric gliomas represent therapeutic targets. 50 supratentorial HGG occurring in children younger than four years were retrieved from the archives of the Brain Tumor Reference Center, Institute of Neuropathology, Bonn University. DNA and RNA were extracted from FFPE tumor samples. Gene fusions were identified on the DNA level by FISH using break-apart probes for ALK, NTRK1, -2, -3, ROS1 and MET and Molecular Inversion Probe (MIP) methodology. On the RNA level, fusion transcripts were detected by targeted RNA sequencing as well as Nanostring assay with fusion-specific probes. 37 supratentorial HGG occurred in the first year of life, 13 HGG between one and four years. 18 cases showed fusions of ALK to different partners; all occurred in the first year of life (18/37, 48.6%). Fusions of ROS1 were found in 5, MET in 3, NTRK1, -2, -3 in 10 cases. 12 cases showed no and two cases novel fusions. The different methods led to comparable results. Only recurrent fusions with known fusion partners were detectable with fusion sequence-specific Nanostring probes and library construction for targeted RNA sequencing failed in a fraction of cases. Break-apart FISH led to reliable results on the next day, and MIP technology represented the most sensitive method for analysis of FFPE samples. Gene fusions involving the tyrosine kinase genes ALK, MET, ROS1 and NTRK1, -2, -3 occurred in 72% of HGG of young children; most frequent were ALK fusions occurring in tumors of infants. DNA-based MIP technology represented the most robust and sensitive assay. A combination of RNA- and DNA-based methods to detect these fusions with high reliability is recommended.

RNA Sequencing Reveals Alterations and Similarities in Cell Metabolism, Hypoxia and Immune Evasion in Primary Cell Cultures of Clear Cell Renal Cell Carcinoma

The treatment of advanced renal cell carcinoma remains a challenge. To develop novel therapeutic approaches, primary cell cultures as an in vitro model are considered more representative than commercial cell lines. In this study, we analyzed the gene expression of previously established primary cell cultures of clear cell renal cell carcinoma by bulk (3’m)RNA sequencing and compared it to the tissue of origin. The objectives were the identification of dysregulated pathways under cell culture conditions. Furthermore, we assessed the suitability of primary cell cultures for studying crucial biological pathways, including hypoxia, growth receptor signaling and immune evasion. RNA sequencing of primary cell cultures of renal cell carcinoma and a following Enrichr database analysis revealed multiple dysregulated pathways under cell culture conditions. 444 genes were significantly upregulated and 888 genes downregulated compared to the tissue of origin. The upregulated genes are crucial in DNA repair, cell cycle, hypoxia and metabolic shift towards aerobic glycolysis. A downregulation was observed for genes involved in pathways of immune cell differentiation and cell adhesion. We furthermore observed that 7275 genes have a similar mRNA expression in cell cultures and in tumor tissue, including genes involved in the immune checkpoint signaling or in pathways responsible for tyrosine kinase receptor resistance. Our findings confirm that primary cell cultures are a representative tool for specified experimental approaches. The results presented in this study give further valuable insights into the complex adaptation of patient-derived cells to a new microenvironment, hypoxia and other cell culture conditions, which are often neglected in daily research, and allow new translational and therapeutic approaches.

C-reactive protein flare predicts response to anti-PD-(L)1 immune checkpoint blockade in metastatic urothelial carcinoma

PURPOSE

Robust biomarkers to predict response to immune checkpoint blockade (ICB) in metastatic urothelial carcinoma (mUC) are still in demand. Recently, early C-reactive protein (CRP) kinetics and especially the novel CRP flare-response phenomenon has been associated with immunotherapy response.

METHODS

We conducted a multicentre observational study comprising 154 patients with mUC treated with ICB to evaluate the predictive value of a previously described on-treatment CRP kinetics: CRP flare responders (at least doubling of baseline CRP within the first month after initiation of ICB followed by a decline below baseline within three months), CRP responders (decline in baseline CRP by ≥ 30% within three months without a prior flare) and the remaining patients as CRP non-responders. CRP kinetics groups were correlated with baseline parameters, PD-L1 status, progression-free survival (PFS) and overall survival (OS).

RESULTS

Objective response was observed in 57.1% of CRP responders, 45.8% of CRP flare responders and 17.9% of CRP non-responders (P < 0.001). CRP flare response was associated with prolonged PFS and OS (P < 0.001). In multivariable Cox regression analysis, CRP flare responders showed a risk reduction of ∼70% for tumour progression and death compared to CRP non-responders. Subgroup analysis of CRP flare responders revealed that patients with a long-flare response (completed flare-response kinetics ≥6 weeks on-treatment) showed even more favourable outcomes following ICB (HR = 0.18, 95%-CI: 0.07-0.48, P < 0.001).

CONCLUSION

CRP (flare)response robustly predicts immunotherapy response and outcomes in mUC independent of PD-L1 status. Thus, early on-treatment CRP kinetics is a promising low-cost and easy-to-implement biomarker to optimise therapy monitoring in patients with mUC treated with ICB.

CD103+ Tissue Resident T-Lymphocytes Accumulate in Lung Metastases and Are Correlated with Poor Prognosis in ccRCC

Clear cell renal cell carcinoma (ccRCC) is a highly immunogenic tumor with variable responses to immune checkpoint therapy. The significance of the immune cell infiltrate in distant metastases, their association with the immune infiltrate in the primary tumors and their impact on prognosis are poorly described. We hypothesized that specific subtypes of immune cells may be involved in the control of metastases and may have an impact on the prognosis of ccRCC. We analyzed the immune microenvironment in ccRCC primary tumors with distant metastases, paired distant metastases and non-metastasized ccRCC (n = 25 each group) by immunohistochemistry. Confirmatory analyses for CD8+ and CD103+ cells were performed in a large ccRCC cohort (n = 241) using a TCGA-KIRC data set (ITGAE/CD103). High immune cell infiltration in primary ccRCC tumors was significantly correlated with the development of distant tumor metastasis (p < 0.05). A high density of CD103+ cells in ccRCC was more frequent in poorly differentiated tumors (p < 0.001). ccRCCs showed high levels of ITGAE/CD103 compared with adjacent non-neoplastic tissue. A higher density of CD103+ cells and a higher ITGAE/CD103 expression were significantly correlated with poor overall survival in ccRCC (log rank p < 0.05). Our results show a major prognostic value of the immune pattern, in particular CD103+ cell infiltration in ccRCC, and highlight the importance of the tumor immune microenvironment.

Inter-observer agreement for the histological diagnosis of invasive lobular breast carcinoma

Invasive lobular breast carcinoma (ILC) is the second most common breast carcinoma (BC) subtype and is mainly driven by loss of E‐cadherin expression. Correct classification of BC as ILC is important for patient treatment. This study assessed the degree of agreement among pathologists for the diagnosis of ILC. Two sets of hormone receptor (HR)‐positive/HER2‐negative BCs were independently reviewed by participating pathologists. In set A (61 cases), participants were provided with hematoxylin/eosin (HE)‐stained sections. In set B (62 cases), participants were provided with HE‐stained sections and E‐cadherin immunohistochemistry (IHC). Tumor characteristics were balanced. Participants classified specimens as non‐lobular BC versus mixed BC versus ILC. Pairwise inter‐observer agreement and agreement with a pre‐defined reference diagnosis were determined with Cohen's kappa statistics. Subtype calls were correlated with molecular features, including CDH1/E‐cadherin mutation status. Thirty‐five pathologists completed both sets, providing 4,305 subtype calls. Pairwise inter‐observer agreement was moderate in set A (median κ = 0.58, interquartile range [IQR]: 0.48–0.66) and substantial in set B (median κ = 0.75, IQR: 0.56–0.86, p < 0.001). Agreement with the reference diagnosis was substantial in set A (median κ = 0.67, IQR: 0.57–0.75) and almost perfect in set B (median κ = 0.86, IQR: 0.73–0.93, p < 0.001). The median frequency of CDH1/E‐cadherin mutations in specimens classified as ILC was 65% in set A (IQR: 56–72%) and 73% in set B (IQR: 65–75%, p < 0.001). Cases with variable subtype calls included E‐cadherin‐positive ILCs harboring CDH1 missense mutations, and E‐cadherin‐negative ILCs with tubular elements and focal P‐cadherin expression. ILCs with trabecular growth pattern were often misclassified as non‐lobular BC in set A but not in set B. In conclusion, subtyping of BC as ILC achieves almost perfect agreement with a pre‐defined reference standard, if assessment is supported by E‐cadherin IHC. CDH1 missense mutations associated with preserved E‐cadherin protein expression, E‐ to P‐cadherin switching in ILC with tubular elements, and trabecular ILC were identified as potential sources of discordant classification.

The Different Immune Profiles of Normal Colonic Mucosa in Cancer-Free Lynch Syndrome Carriers and Lynch Syndrome Colorectal Cancer Patients

BACKGROUND & AIMS

Owing to the high load of immunogenic frameshift neoantigens, tumors arising in individuals with Lynch syndrome (LS), the most common inherited colorectal cancer (CRC) syndrome, are characterized by a pronounced immune infiltration. However, the immune status of normal colorectal mucosa in LS is not well characterized. We assessed the immune infiltrate in tumor-distant normal colorectal mucosa from LS CRC patients, sporadic microsatellite-unstable (MSI) and microsatellite-stable (MSS) CRC patients, and cancer-free LS carriers.

METHODS

CD3-positive, FOXP3-positive, and CD8-positive T cells were quantified in, respectively, 219, 233, and 201 formalin-fixed paraffin-embedded (FFPE) normal colonic mucosa tissue sections from CRC patients and cancer-free LS carriers and 26, 22, and 19 LS CRCs. CD3-positive T cells were also quantified in an independent cohort of 97 FFPE normal rectal mucosa tissue sections from LS carriers enrolled in the CAPP2 clinical trial. The expression of 770 immune-relevant genes was analyzed in a subset of samples with the use of the NanoString nCounter platform.

RESULTS

LS normal mucosa specimens showed significantly elevated CD3-, FOXP3-, and CD8-positive T-cell densities compared with non-LS control specimens. Gene expression profiling and cluster analysis revealed distinct immune profiles in LS carrier mucosa with and without cancer manifestation. Long-term follow-up of LS carriers within the CAPP2 trial found a correlation between mucosal T-cell infiltrate and time to subsequent tumor occurrence.

CONCLUSIONS

LS carriers show elevated mucosal T-cell infiltration even in the absence of cancer. The normal mucosa immune profile may be a temporary or permanent tumor risk modifier in LS carriers.

German S3 Evidence-Based Guidelines on Focal Therapy in Localized Prostate Cancer: The First Evidence-Based Guidelines on Focal Therapy

BACKGROUND

Focal therapy (FT) is an option to treat localized prostate cancer (PCa) and preserve healthy prostate tissue in order to reduce known side effects from primary whole-gland treatment. The available FT modalities are manifold. Until now, national and international PCa guidelines have been cautious to propose recommendations regarding FT treatment since data from prospective controlled trials are lacking for most FT modalities. Moreover, none of the international guidelines provides a separate section on FT. In this purpose, we provide a synopsis of the consensus-based German S3 guidelines for a possible international use.

SUMMARY

The recently published update of the German S3 guidelines, an evidence- and consensus-based guideline, provides a section on FT with recommendations for diagnostic work-up, indications, modalities, and follow-up. This section consists of 12 statements and recommendations for FT in the treatment of localized PCa. Key Message: The German S3 guidelines on PCa are the first to incorporate recommendations for FT based on evidence and expert consensus including indication criteria for FT, pretreatment, and follow-up diagnostic pathways as well as an extended overview of FT techniques and the current supportive evidence.

Overexpression of Parkin in clear cell renal cell carcinoma decreases tumor aggressiveness by regulating CKS2 levels

Low expression levels of the E3 ubiquitin-protein ligase Parkin (PARK2) are exhibited in several cancer entities, including clear cell renal cell carcinoma (ccRCC), and are associated with poor prognosis; however, PARK2 can also function as a tumor suppressor gene. The aim of the present study was to thoroughly investigate the effects of PARK2 overexpression in ccRCC cell lines and to determine its effects on malignancy by conducting functional assays such as cell cycle analysis, apoptosis analysis, migration and invasion assays. Furthermore, liquid chromatography-mass spectrometry was used to decipher potential targets of PARK2 that may influence the behavior of ccRCC tumor cells. In addition, ccRCC tumor tissues from a patient cohort were examined in tissue microarrays to find correlations between different clinical parameters. In the present study, it was demonstrated that the induction of PARK2 resulted in a less aggressive phenotype, as indicated by lower migration and invasion in ccRCC cell lines. Mass spectrometry revealed decreased levels of 29 proteins in cells with PARK2 overexpression, including CDC28 protein kinase regulatory subunit 2 (CKS2), which is highly expressed in numerous types of cancer. The link between the function of PARK2 as an E3 ubiquitin ligase and the low expression levels of CKS2 was investigated by mutating the catalytic domain of the PARK2 gene, and it was found that the effect of decreased migration was abolished in 786-O and RCC-MH ccRCC cell lines. CKS2 silencing decreased migratory ability of the cells. Furthermore, it was revealed that high CKS2 levels are associated with high tumor grading in patient samples and lower patient survival. In conclusion, the results from the present study indicated that PARK2 may signal via CKS2 to affect tumor behavior. In consequence, CKS2 may be a biomarker in ccRCC and may also serve as potential target for ccRCC therapy.